Efficient way to delete entire row if cell doesn't contain '#' [duplicate] - vba

Question

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Delete Row based on Search Key VBA
(3 answers)
Closed 8 years ago.
I'm creating a fast sub to do a validity check for emails. I want to delete entire rows of contact data that do not contain a '#' in the 'E' Column. I used the below macro, but it operates too slowly because Excel moves all the rows after deleting.
I've tried another technique like this: set rng = union(rng,c.EntireRow), and afterwards deleting the entire range, but I couldn't prevent error messages.
I've also experimented with just adding each row to a selection, and after everything was selected (as in ctrl+select), subsequently deleting it, but I could not find the appropriate syntax for that.
Any ideas?
Sub Deleteit()
Application.ScreenUpdating = False
Dim pos As Integer
Dim c As Range
For Each c In Range("E:E")
pos = InStr(c.Value, "#")
If pos = 0 Then
c.EntireRow.Delete
End If
Next
Application.ScreenUpdating = True
End Sub

Answer 1

You don't need a loop to do this. An autofilter is much more efficient. (similar to cursor vs. where clause in SQL)
Autofilter all rows that don't contain "#" and then delete them like this:
Sub KeepOnlyAtSymbolRows()
Dim ws As Worksheet
Dim rng As Range
Dim lastRow As Long
Set ws = ActiveWorkbook.Sheets("Sheet1")
lastRow = ws.Range("E" & ws.Rows.Count).End(xlUp).Row
Set rng = ws.Range("E1:E" & lastRow)
' filter and delete all but header row
With rng
.AutoFilter Field:=1, Criteria1:="<>*#*"
.Offset(1, 0).SpecialCells(xlCellTypeVisible).EntireRow.Delete
End With
' turn off the filters
ws.AutoFilterMode = False
End Sub
NOTES:
.Offset(1,0) prevents us from deleting the title row
.SpecialCells(xlCellTypeVisible) specifies the rows that remain after the autofilter has been applied
.EntireRow.Delete deletes all visible rows except for the title row
Step through the code and you can see what each line does. Use F8 in the VBA Editor.

Answer 2

Have you tried a simple auto filter using "#" as the criteria then use
specialcells(xlcelltypevisible).entirerow.delete
note: there are asterisks before and after the # but I don't know how to stop them being parsed out!

Answer 3

Using an example provided by user shahkalpesh, I created the following macro successfully. I'm still curious to learn other techniques (like the one referenced by Fnostro in which you clear content, sort, and then delete). I'm new to VBA so any examples would be very helpful.
Sub Delete_It()
Dim Firstrow As Long
Dim Lastrow As Long
Dim Lrow As Long
Dim CalcMode As Long
Dim ViewMode As Long
With Application
CalcMode = .Calculation
.Calculation = xlCalculationManual
.ScreenUpdating = False
End With
With ActiveSheet
.Select
ViewMode = ActiveWindow.View
ActiveWindow.View = xlNormalView
.DisplayPageBreaks = False
'Firstrow = .UsedRange.Cells(1).Row
Firstrow = 2
Lastrow = .Cells(.Rows.Count, "E").End(xlUp).Row
For Lrow = Lastrow To Firstrow Step -1
With .Cells(Lrow, "E")
If Not IsError(.Value) Then
If InStr(.Value, "#") = 0 Then .EntireRow.Delete
End If
End With
Next Lrow
End With
ActiveWindow.View = ViewMode
With Application
.ScreenUpdating = True
.Calculation = CalcMode
End With
End Sub

Answer 4

When you are working with many rows and many conditions, you better off using this method of row deletion
Option Explicit
Sub DeleteEmptyRows()
Application.ScreenUpdating = False
Dim ws As Worksheet
Dim i&, lr&, rowsToDelete$, lookFor$
'*!!!* set the condition for row deletion
lookFor = "#"
Set ws = ThisWorkbook.Sheets("Sheet1")
lr = ws.Range("E" & Rows.Count).End(xlUp).Row
ReDim arr(0)
For i = 1 To lr
If StrComp(CStr(ws.Range("E" & i).Text), lookFor, vbTextCompare) = 0 then
' nothing
Else
ReDim Preserve arr(UBound(arr) + 1)
arr(UBound(arr) - 1) = i
End If
Next i
If UBound(arr) > 0 Then
ReDim Preserve arr(UBound(arr) - 1)
For i = LBound(arr) To UBound(arr)
rowsToDelete = rowsToDelete & arr(i) & ":" & arr(i) & ","
Next i
ws.Range(Left(rowsToDelete, Len(rowsToDelete) - 1)).Delete Shift:=xlUp
Else
Application.ScreenUpdating = True
MsgBox "No more rows contain: " & lookFor & "or" & lookFor2 & ", therefore exiting"
Exit Sub
End If
If Not Application.ScreenUpdating Then Application.ScreenUpdating = True
Set ws = Nothing
End Sub

Answer 5

Instead of looping and referencing each cell 1 by 1, grab everything and put it into a variant array; Then loop the variant array.
Starter:
Sub Sample()
' Look in Column D, starting at row 2
DeleteRowsWithValue "#", 4, 2
End Sub
The Real worker:
Sub DeleteRowsWithValue(Value As String, Column As Long, StartingRow As Long, Optional Sheet)
Dim i As Long, LastRow As Long
Dim vData() As Variant
Dim DeleteAddress As String
' Sheet is a Variant, so we test if it was passed or not.
If IsMissing(Sheet) Then Set Sheet = ActiveSheet
' Get the last row
LastRow = Sheet.Cells(Sheet.Rows.Count, Column).End(xlUp).Row
' Make sure that there is work to be done
If LastRow < StartingRow Then Exit Sub
' The Key to speeding up the function is only reading the cells once
' and dumping the values to a variant array, vData
vData = Sheet.Cells(StartingRow, Column) _
.Resize(LastRow - StartingRow + 1, 1).Value
' vData will look like vData(1 to nRows, 1 to 1)
For i = LBound(vData) To UBound(vData)
' Find the value inside of the cell
If InStr(vData(i, 1), Value) > 0 Then
' Adding the StartingRow so that everything lines up properly
DeleteAddress = DeleteAddress & ",A" & (StartingRow + i - 1)
End If
Next
If DeleteAddress <> vbNullString Then
' remove the first ","
DeleteAddress = Mid(DeleteAddress, 2)
' Delete all the Rows
Sheet.Range(DeleteAddress).EntireRow.Delete
End If
End Sub